Solving a mouldy, old problem

We are making the seasonal shift from throwing open windows and letting in the summer sea breeze to shutting out cold winter winds.

The challenge is to retain warmth while avoiding humidity indoors.

Dampness, condensation and mould can cause health problems, as well as nasty smells and damage to homes. Any issues should be investigated and the moisture source stopped as soon as possible.

The main reason for mould growth is excess moisture coming from either inside or outside the home.

Building defects should be considered, but the answer may simply be proper ventilation and an understanding of moisture build up.

Water penetration can happen from outside the building such as rain leaking in through the roof or rising damp through walls.

Water can also enter from wall cavities due to insufficient weep holes. In homes with cavity masonry walls, weep holes are sometimes installed just above the slab on each level and above openings like doors and windows.

If weep holes are blocked, water can’t get out and may pass through to the internal wall. Sometimes homeowners unintentionally block weep holes by creating raised garden beds or installing planter boxes against external walls.

In multi-storey buildings water can come in from an upper floor, if waterproofing fails, from wet areas or a balcony above.

Plumbing leaks can be a contributing factor. Failure of waterproofing membranes in prefabricated shower units – often not immediately noticeable – can allow water into masonry walls.

Condensation and inadequate ventilation, however, are perhaps the most common reason for mould problems.

Tumble dryers and hot, steamy showers are prime causes of heavy moisture build up.

The moist air needs to be vented from a room by using an exhaust fan or opening doors and windows.

Airing out rooms may sound like a simple fix but in some ways it’s not.

Exhaust fans can be noisy and annoying. It’s easy to forget to turn them on. Security, privacy and the weather are all good reasons for keeping windows and doors shut. So, unfortunately, exhaust fans tend to be underused and windows and doors stay locked.

The fact remains that good maintenance and household habits can avoid a lot of trouble with mould.

Builders are responsible for construction faults. Homeowners are responsible for maintenance.

A huge amount of time and effort goes into a new home and it’s a valuable asset, so it’s worth looking after. An understanding of care and upkeep can help people enjoy their home for many years.

Q&A with MBA Technical Building Services Manager Jason Robertson

The Question

I have a block I am building on with no deep sewer available. I was wondering if I could have an eco toilet instead of a septic system with leach drains/soakwells?

The Answer

It is possible, yes.

Eco toilets or waterless/composting toilets certainly are getting more popular.

They can offer an alternative to a conventional flushing toilet. Some features include being odourless and water-saving. In addition, other environmental benefits include providing the property owner with nutrient dense compost for gardening treatments.

With conventional apparatus, considerations sometimes must be given to their location from other structures, including vehicular traffic such as driveways. It must be pointed out, however, that conventional systems do have the ability to be in such areas with trafficable lids.

They work by having moisture being managed through drainage and evaporation systems, which remove all excess liquid from the solids. Further, oxygen is regulated using low-wattage ventilation systems which aerate the compost and, importantly, serve to evacuate any odours from the toilet room.

With any effluent disposal system, there are regulations that must be adhered to. It is recommended in the first instance you speak with your council’s environmental health officer.

There are often multiple considerations to be taken into account, which will determine what types of system are appropriate and can actually be installed.

The Department of Health has a published list of approved waterless/composting systems. The Approved waterless toilets article can be found online at ww2.health.wa.gov.au.

Happy sustainable building!

CONTACT Master Builders WA, 9476 9800, www.mbawa.com